C语言 如何在C中将字符串转换为十六进制值
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How to convert string to hex value in C
提问by Allamaprabhu
I have string "6A" how can I convert into hex value 6A?
我有字符串“6A”如何转换为十六进制值 6A？
Please help me with solution in C
请帮我解决C中的问题
I tried
我试过
char c[2]="6A"
char *p;
int x = atoi(c);//atoi is deprecated
int y = strtod(c,&p);//Returns only first digit,rest it considers as string and
//returns 0 if first character is non digit char.
回答by Weather Vane
The question
问题
"How can I convert a string to a hex value?"
“如何将字符串转换为十六进制值？”
is often asked, but it's not quite the right question. Better would be
经常被问到，但这不是一个正确的问题。更好的是
"How can I convert a hex string to an integer value?"
“如何将十六进制字符串转换为整数值？”
The reason is, an integer (or char or long) value is stored in binary fashion in the computer.
原因是，整数（或 char 或 long）值以二进制方式存储在计算机中。
"6A" = 01101010
It is only in human representation (in a character string) that a value is expressed in one notation or another
只有在人类表示中（在字符串中），值才能以一种或另一种表示法表示
"01101010b" binary
"0x6A" hexadecimal
"106" decimal
"'j'" character
all represent the same value in different ways.
都以不同的方式表示相同的值。
But in answer to the question, how to convert a hex string to an int
但是在回答这个问题时，如何将十六进制字符串转换为 int
char hex[] = "6A"; // here is the hex string
int num = (int)strtol(hex, NULL, 16); // number base 16
printf("%c\n", num); // print it as a char
printf("%d\n", num); // print it as decimal
printf("%X\n", num); // print it back as hex
Output:
输出：
j
106
6A
